/*
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 *
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 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
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 * GPL Classpath Exception:
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package org.glassfish.jersey.spi;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import javax.ws.rs.DefaultValue;

/**
 * Read a string value and convert to a Java type.
 * <p>
 * A {@link StringValueReaderProvider} is responsible for providing an instance
 * of this interface.
 * <p>
 * If annotated with {@link ValidateDefaultValue ValidateDefaultValue(true)} or
 * if the annotation is absent then the reader will be used to eagerly convert a
 * {@link DefaultValue default value} (if any) by calling the {@link #fromString(java.lang.String)}
 * transformation method, perhaps at initialization, before any value &ndash;
 * default or otherwise &ndash; is actually required. This enables the early
 * reporting of errors for default values. If annotated with {@code ValidateDefaultValue(false)}
 * then the reader will not be used to eagerly convert a default value (if any).
 *
 * @param <T> the supported Java type produced as a result of string value conversion.
 *
 * @author Paul Sandoz
 * @author Marek Potociar (marek.potociar at oracle.com)
 *
 */
public interface StringValueReader<T> {

    /**
     * Declares whether validation of a default value should occur before any
     * value &ndash; default or otherwise &ndash; is actually required.
     */
    @Target({ElementType.TYPE})
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    public static @interface ValidateDefaultValue {

        boolean value() default true;
    }

    /**
     * Read a string value and convert to a Java type.
     *
     * @param value the string value to be converted.
     * @return the instance of the supported Java type produced as a result of conversion.
     */
    T fromString(String value);
}